BRPI1011219B1 - PROCESS FOR PRODUCING LIQUID PRODUCTS FROM BIOMASS - Google Patents

Abstract

process for producing liquid products from biomass A self-sustaining process for producing high quality liquid fuels from biomass in which biomass is hydropyrolyzed in a reactor containing molecular hydrogen and a deoxygenation catalyst, producing a partially deoxygenated hydropyrolysis liquid. , which is hydrogenated using a hydroconversion catalyst, producing a substantially fully deoxygenated hydrocarbon liquid and a gas mixture comprising co and light (c1-c3) hydrocarbon gases. The gas mixture is reformed in a steam reformer, producing reformed molecular hydrogen, which is then introduced into the reactor for biomass hydropyrolysis. The deoxygenated hydrocarbon liquid product is further separated to produce diesel fuel, gasoline, or gasoline and diesel fuel blending components.

Description

BACKGROUND OF THE INVENTION Field of the Invention This invention relates to an integrated process for thermally transforming biomass into high quality liquid fuels. As used herein, the term "biomass" refers to biological materials derived from living or dead organisms and includes lignocellulosic materials such as wood, aquatic materials such as algae, aquatic plants, algae, and animal by-products such as commercial value, fats and sewage sludge. In one aspect, this invention relates to a substantially self-sustaining process for the creation of high quality liquid fuels from biomass. In another aspect, this invention relates to a multistage hydropyrrolysis process for the creation of high quality liquid fuels from biomass. In another aspect, this invention relates to a hydro-pyrolysis process for transforming biomass into high quality liquid fuels in which all process fluids are supplied by biomass. In another aspect, this invention relates to a hydro pyrolysis process for transforming biomass into high quality liquid fuels wherein the process outputs are substantially only the liquid product and CO2. In another aspect, this invention relates to an integrated process for producing gasoline and diesel fuels from the biomass using a hydrocracking catalyst.

Description of Related Art Conventional pyrolysis of biomass, typically rapid pyrolysis, does not use or require H2 or catalysts and produces a dense, acidic and reactive liquid product containing water, oils and carbonized material formed during the process. Due to the fact that rapid pyrolysis is most typically performed in an inert atmosphere, most of the oxygen present in the biomass is transported to the oils produced in the pyrolysis, which increases its chemical reactivity. Unstable liquids produced by conventional pyrolysis tend to thicken over time and may also react to a point where hydrophilic and hydrophobic phases form. Dilution of pyrolysis liquids with methanol or other alcohols has been shown to reduce the activity and viscosity of the oil, but this approach is not considered to be practically and economically feasible because large amounts of unrecoverable alcohol would be required to produce and carry large amounts of pyrolysis.

In the conventional pyrolysis carried out in an inert environment, the water-miscible liquid product is highly oxygenated and reactive, with total acid number (TAN) in the range of 100-200, has low chemical stability of polymerization, is incompatible with hydrocarbons oil derivatives due to water miscibility and very high oxygen content, of the order of about 40% by weight, and has a low calorific value. As a result, the transportation and use of this product is problematic and it is difficult to raise the quality of this product to a liquid fuel due to the retrograde reactions which normally occur in conventional pyrolysis and conventional rapid pyrolysis. In addition, removal of carbonized material generated by conventional pyrolysis from the pyrolysis liquid product presents a technical challenge because of the large amounts of oxygen and free radicals in the pyrolysis vapors, which remain highly reactive and form a tar-like material when they enter intimate contact with the particles of carbonized material on the surface of a filter. Consequently, the filters used to separate the carbonized material from the hot vapors from the pyrolysis entropy rapidly due to the reactions of the carbonized material and oil occurring on and within the layer of carbonized material on the surface of the filter.

Improving the quality of the pyrolysis oils produced through conventional rapid pyrolysis by hydroconversion consumes large amounts of H2, and the extreme process conditions make it uneconomical. Reactions are inherently out of balance because, due to the high pressures required, too much water is created at the same time that too much H2 is consumed. In addition, hydroconversion reactors often clog due to the coke precursors present in the pyrolysis oils or the coke produced as a result of the catalysis.

In general, hydropyrolysis is a catalytic pyrolysis process performed in the presence of molecular hydrogen. Ordinarily, the goal of conventional hydroepirolysis processes has been to maximize liquid yield in a single step. However, in a known case, a second reaction step was added, whose objective was to maximize the yield, maintaining the high oxygen removal. However, even this approach compromises the economy, it creates a system that requires an external source of H2, and must be performed under excessive internal pressures. In addition to requiring a continuous inlet of hydrogen, such conventional hydro-pyrolysis processes produce excessive amounts of H2O, which must then be eliminated.

Accordingly, it is an object of the present invention to provide a self-sustaining balanced process for the conversion of biomass to a liquid product by means of hydrotropyysis. By self-sustaining, we mean that, once started, the process does not require any additional input of reagents, heat, or energy from external sources.

It is a further object of this invention to provide a process for the conversion of biomass into a liquid product using hydropyrosolysis wherein the total production of the process as a whole is substantially only the liquid and CO2 production. As used herein, the term "liquid product" refers to the normally-C 4 + liquid hydrocarbon products produced by the process of this invention.

These and other objects of the present invention are achieved by a self-sustaining multistage process for the production of liquid productions from biomass wherein the biomass is hydrolyzed in a reactor containing molecular hydrogen and a deoxygenation catalyst, producing a liquid partially deoxygenated hydrotropyysis, carbonized material, and heat in the first stage of the process. The partially deoxygenated hydrotropyysis liquid is hydrogenated using a hydroconversion catalyst, producing a substantially fully deoxygenated hydrocarbon liquid, a gaseous mixture comprising CO and light hydrocarbon gases (C 1 -C 3), and heat in the second stage of the process. The gaseous mixture is then reformed into a steam reformer, producing reformed molecular hydrogen. The reformed molecular hydrogen is then introduced into the reaction vessel for additional hydropyrolysis of biomass.

In order to provide a self-sustained process, the hydro-pyrolysis and hydroconversion steps are operated under conditions where about 30-70% oxygen in the biomass is converted to H2O and about 30-70% of the oxygen is converted to CO and CO2. That is, the proportion of oxygen in the H2 O produced therein relative to the oxygen in the CO and CO2 produced therein is in the range of about 0.43 to about 2.2. Preferably, the process pressures and the hydropyrrole and hydroconverting steps are in the range of from about 6.89 barg to about 100 psig (100 psig) and are practically the same for both steps. Pressures greater than about 55.2 barg (800 psig) result in a higher yield of liquid product, which is the driving force behind the operating parameters employed by conventional processes to maximize the yield of the liquid product, however such pressures more high temperatures also produce larger amounts of water as a result of which the process as a whole is conducted out of balance, requiring, for example, the introduction of additional hydrogen into the hydro-pyrolysis reactor from an external source to complete the process. In addition, the excess water produced at the higher pressures needs to be further purified and discarded. Preferably, the temperatures for the hydropyrolysis and hydroconversion steps are in the range of about 343Â ° C (650Â ° F) to about 538Â ° C (1000Â ° F).

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and features of this invention will be better understood from the detailed description below, taken in conjunction with the drawings, wherein: Figure 1 is a schematic flow diagram of the self-sustaining process for producing liquid fuels from biomass according to one embodiment of this invention. Figure 2 is a schematic flow diagram of the self-sustaining process for producing liquid fuels from biomass using a hydrocracking catalyst wherein hydrocracking occurs downstream of the hydro conversion step according to one embodiment of the present invention; Figure 3 is a schematic flow diagram of the self-sustaining process for producing liquid fuels from the biomass using a hydrocracking catalyst occurring upstream of the hydroconversion stage separator according to one embodiment of the present invention; Figure 4 is a schematic flow diagram of the self-sustaining process for producing liquid fuels from the biomass using a hydrocracking catalyst in which it occurs upstream of the hydroconversion stage separator according to another embodiment of the present invention; Figure 5 is a schematic flow diagram of the self-sustaining process for producing liquid fuels from the biomass using a hydrocracking catalyst wherein hydrocracking occurs downstream of the hydroconversion step according to one embodiment of the present invention; Figure 6 is a schematic flow diagram of the self-sustaining process for producing liquid fuels from the biomass using a hydrocracking catalyst wherein the hydrocracking is performed in parallel with the hydroconversion step according to one embodiment of this invention; Figure 7 is a schematic flow diagram of the self-sustaining process for producing liquid fuels from the biomass using a hydrocracking catalyst in place of the hydro-pyrolysis catalyst according to one embodiment of this invention; and Figure 8 is a schematic flow diagram of the self-sustaining process for producing liquid fuels from the biomass using a hydrocracking catalyst instead of the hydroconversion catalyst according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [011] The process of the present invention, shown in the figure. 1 is a multistage, compact, balanced, integrated process for thermally converting biomass to gasoline plus diesel liquid product suitable for use as carrier fuel without the need to be externally provided with H2, CH4, or water. The first stage or reaction step of this process employs a catalytically reinforced pressurized hydrotropyysis reactor 10 to create a low carbon partially deoxygenated hydrotropy liquid product from which the carbonized material is removed. The second reaction stage (after removal of carbonized material) employs a hydroconversion reactor 11 in which a hydroconversion step is performed substantially at the same pressure as that of the first reaction stage. The product from the second reaction stage is then cooled and separated into liquid and gaseous fractions using high pressure separators 12, 13 and low pressure separator 14. Further light gases of the type C1-C3 produced in the two stages are then reformed in steam in a steam reformer to produce H2 using water which is also produced in the process. A key aspect of this invention is that the thermal energy required in the process is provided by the reaction heat of the deoxygenation reaction, which is exothermic, and occurs in both the first and second stages. Another fundamental aspect of this invention is that the biomass feed does not need to be intensively dried and, in fact, the addition of water either in the feed or as a separate feed is advantageous to the process because it stimulates the formation of H2 in-situ through a water displacement reaction.

The balanced, integrated process of this invention is performed under conditions which balance the decarboxylation, decarbonylation, and hydrodeoxygation levels such that 30 to 70% of the oxygen in the biomass is discarded as CO and CO 2 and the remaining 30 to 70% of the oxygen in the biomass is rejected as H2O at the end of the process where it is easily separated from the hydrophilic liquid products produced by the process for use in the reform process. In general, after reforming the light gases produced by the first two stages of the process with the water produced by the process, more than 95% of the oxygen in the process is rejected as CO2.

The particular equilibrium of the reactions is critical to the process of this invention and is achieved by selecting the appropriate catalysts and process conditions at each step. While each step of the process of this invention may produce a variety of products, depending upon the catalyst, pressure, temperature and time in the streams employed, only when such processes are integrated into the specific series of process steps and conditions of this invention is it possible to provide a balanced process in which the entire H2, CH4 and water demands of the whole process can be met by biomass, which is crucial for the creation of a fungible fuel that can be traded at a reasonable cost.

In the first step of the process of this invention shown in Figure 1, biomass and molecular hydrogen are introduced into a reactor 10 which contains a deoxygenation catalyst, a vessel in which the biomass undergoes hydrotropyysis, producing a product flow comprising a liquid product low dehydropyrolysis of carbonized, partially deoxygenated material, pyrolysis vapors (type C1-C3 gases), H2O, CO, CO2 and H2. While any reactor suitable for hydropyrolysis can be employed, the preferred reactor utilizes a fluidized bed reactor. The hydro-pyrolysis step employs rapid heating (greater than about 100 W / m 2) of the biomass feed such that the residence time of the pyrolysis vapors in the reactor is less than about 5 minutes. In contrast to this, the residence time of the carbonized material is relatively long because it is not removed through the bottom of the reactor and therefore must be reduced in particle size until the particles are small enough to allow them to be carried out with the exhaust vapors near the top of the reactor.

The biomass feed used in the process of this invention may be in the form of loose biomass particles having a majority of particles preferably smaller than about 3 millimeters in size or in the form of a biomass / liquid pulp. However, it will be appreciated by those of ordinary skill in the art that the biomass feed can be pretreated or otherwise processed in such a way that larger sized particles can be accommodated. Suitable means for introducing the biomass feed into the hydrotropyolysis reactor include, but are not limited to, a worm axis, fast moving gas stream (greater than about 5 m / s), such as inert gases and H2, and constant displacement pumps, impellers, or turbine type pumps.

Hydropyrrolysis is performed in the reactor at a temperature in the range of about 800Â ° F (327Â ° C) to about 1000Â ° F (538Â ° C) and at a pressure in the range of 100 psig (6.89 barg) to about 55.2 barg (800 psig). The heating rate of the biomass is preferably greater than about 100 W / m 2. The mass hourly space velocity (WHSV) in biomass gram / gram of catalyst / hour in that step is in the range of about 0.2 to about 10. In conventional hydro-pyrolysis processes, as noted previously, the goal is to maximize the yield of the liquid product, which requires operation at substantially higher pressures, for example, on the order of 138 barg (2000 psig). This is because decarboxylation is favored at low pressures while hydrodeoxygenation is favored at high operating pressures. By maintaining pressures in the process of this invention in the range of from 100 psig to 100 psig, more preferably at about 50 psig, decarboxylation but the yield of the liquid product is reduced. At higher pressures, the hydrodeoxygenation is favored and the reactions become unbalanced.

As indicated above, in the hydro-pyrolysis step of this invention, the feed of the solid biomass is heated rapidly, preferably in a hot fluidized bed, resulting in comparable liquid product yield and possibly better than the yields obtained with the rapid pyrolysis conventional. However, hydropyrrolysis vapors are now in the presence of a catalyst and a high partial pressure of H2 within the fluidized bed which provides the hydrogenation activity and also some deoxygenation activity. Hydrogenation activity is highly desirable for the prevention of the polymerization of reactive olefins, thereby reducing the formation of unstable free radicals. Similarly, the deoxygenation activity is important so that the heat of the hydrolysis reaction is provided by the exothermic deoxygenation reaction, thereby suppressing the need for external heating. The advantage of hydropyriolysis over existing pyrolytic processes is that hydropyrolysis avoids retrograde pyrolysis reactions, which is usually carried out in an inert atmosphere, most certainly in the absence of H2, and generally in the absence of a catalyst, thereby promoting undesirable formation of polynuclear aromatics, free radicals and olefinic compounds that are not present in the original biomass.

The first stage of the first stage hydrotropyysis step of this invention operates at a warmer temperature than is typical of a conventional hydro conversion process as a result of which the biomass is rapidly de-volatilized. Thus, the step requires an active catalyst to stabilize the hydro-pyrolysis vapors, but not so active that it rapidly forms coke. Catalyst particle sizes are preferably greater than about 100 Âμm. Although any deoxygenation catalyst suitable for use in the temperature range of this process can be employed in the hydropyrolysis step, the catalysts according to preferred embodiments of the present invention are as follows: [019] Glass-ceramic catalysts: Glass-ceramic type catalysts are extremely strong and wear resistant and can be prepared as thermally impregnated (i.e., supported) or as bulk catalysts.

When employed as Ni / NiO catalysts, Ni / NiO, or as base-glass-ceramic catalysts Co, the resulting catalyst is a friction resistant version of a readily available, yet mild, conventional NiMo, Ni / NiO, or Base Co The Ni / NiO, or base-Co, sulfated glass-ceramic catalysts are particularly suitable for use in a hot fluidized bed, since such materials can provide the catalytic effect of a conventional supported catalyst, but in a much more robust and resistant to friction. In addition, due to the friction resistance of the catalyst, the biomass and carbonized material are simultaneously ground to the smallest form as the hydro-pyrolysis reaction evolves inside the reactor. Thus, the carbonized material that is ultimately recovered is substantially free of catalyst contaminants from the catalyst due to the extremely high resistance and resistance to the friction of the catalyst. The rate of friction resistance of the catalyst will typically be less than about 2% by weight per hour, preferably less than about 1% by weight per hour as determined in a high jet glass test rate test velocity.

[020] Nickel phosphide catalyst: Nickel phosphide catalysts do not require sulfur to function and therefore will be as active in a sulfur free environment as in an environment containing H2S, COS and other sulfur containing compounds. Therefore, this catalyst will be as active for biomass, which contains little or no sulfur present, or as biomass that does not contain sulfur (eg corn straw). This catalyst may be impregnated into carbon as a separate catalyst or impregnated directly into the biomass supply itself.

[021] Bauxite: Bauxite is an extremely cheap material and therefore can be used as a disposable catalyst. Bauxite can also be impregnated with other materials, such as Ni, Mo, or be sulphited as well.

[022] Small-size silica-alumina catalyst sprayed impregnated with NiMo or CoMo and sulfided to form a hydroconversion catalyst: Commercially available NiMo or CoMo catalysts are usually supplied as pellets of large sizes from 1/8 to 1 / 16 inch for use on boiling beds. In the present case, NiMo is impregnated in a spray-dried silica-alumina catalyst and used in a fluidized bed. Such a catalyst exhibits greater strength than a conventional NiMo or CoMo catalyst and may be of the right size for use in a fluidized bed.

[023] Amid the steps of hydrotropyysis and hydroconversion, the carbonized material is removed from the hydrocarbon liquid product. Removal of the carbonized material has been an important barrier in rapid pyrolysis since the carbonized material tends to cover the filters and react with the oxygenated pyrolysis vapors to form viscous coatings which can plug the filters in the hot process. The carbonized material may be removed in accordance with the process of this invention by filtration of the steam stream, or by means of filtration of a boiling-bed-washing step. Retropulsation may be employed in the removal of the carbonized material deposited in the filters, provided that the hydrogen used in the process of this invention sufficiently reduces the reactivity of the pyrolysis vapors. Electrostatic precipitation, inertial separation, magnetic separation, or a combination of these technologies may also be used to remove the charred material and ash particles from the heated steam stream prior to cooling and condensation of the liquid product.

[024] Because of their resistance to friction, glass-ceramic type catalysts are more easily separated from the carbonized material by means of inertial separation energy technologies which typically employ processes of energy impact, interception, and / or diffusion sometimes combined with electrostatic precipitation to separate, concentrate and collect the carbonized material in the form of a secondary stream for recovery. An additional virtue of such materials is that, because they are susceptible to magnetic separation (in a reduced state, being attracted to a permanent or electrically induced magnetic field), magnetic techniques as well as combinations of magnetic, inertial, and electrostatic media may be employed to separate the carbonized material from these catalysts which are not possible to apply with softer materials.

[025] According to one embodiment of this invention, hot gas filtration can be used to remove the carbonized material. In this case, because the hydrogen stabilizes the free radicals and saturates the olefins, the dust cake captured in the filters can be more easily cleaned than the carbonized material removed in the hot filtration of the aerosols produced in the conventional fast pyrolysis. According to another embodiment of this invention, the carbonized material is removed by bubbling the gas produced in the first stage through a recirculating liquid. The recirculated liquid used is the high boiling point portion of the finished oil from that process being thus a stabilized, fully saturated (hydrogenated) oil having a station point typically above 650Â ° F (343Â ° C). The carbonized or fine catalyst material from the first reaction stage is captured in that liquid. A portion of the liquid may be filtered to remove the fines and a portion may be recycled back to the first stage of the hydrotropyolysis reactor. An advantage of using a recirculating liquid is that it provides a way of lowering the temperature of the process vapors which carry the carbonized material from the first reaction stage to the desired temperature for the hydroconversion step of the second reaction stage while removing at the same time the finely particulate material of the carbonized material and the catalyst. Another advantage of using liquid filtration is that the use of hot gas filtration with its inherent well-documented filter cleaning problems is completely avoided.

[026] According to one embodiment of this invention, the large NiMo or CoMo catalysts, implanted in a seeding bed, are used for removal of the carbonized material to provide additional deoxygenation simultaneously with the removal of fine particles. The particles of this catalyst should be large, preferably about 1/8 to 1/16 inch in size, thereby making them readily separable from the fines of the carbonized material carried from the first reaction stage, which are typically less than 200 mesh (about 70 microns).

After removal of the carbonized material, C4 + type liquid vapors together with H2, CO, CO2, H2O and C1-C3 type gases from the first stage hydrocolysis stage are introduced into a reactor 11 of the second stage in which they are subjected to a hydroconversion step in a second reaction stage, which is preferably carried out at a lower temperature 260 ° C to 455 ° C (500-850 ° F) than the hydrophilic stage of the first stage of reaction to increase the useful life of the catalyst and substantially at the same pressure 6.89 barg at 55.2 barg (100-800 psig) as in the hydrotropyysis step of the first reaction stage. The hourly mass space velocity (WHSV) for this step is in the range of about 0.2 to about 3. The catalyst used in this step should be protected from Na, K, Ca, P, and other metals present in the biomass which may to poison the catalyst, which will tend to increase the useful life of the catalyst. This catalyst must also be protected from olefins and free radicals by improving the catalytic level achieved in the first stage of the first reaction stage. The catalysts typically selected for this step are catalysts of high hydroconversion activity; for example, NiMo sulfide catalysts and CoMo sulfates. In this stage of reaction, the catalyst is used to catalyze a water-gas displacement reaction of CO + H2O to produce CO2 + H2, thereby allowing the in-situ production of hydrogen in reactor 11 of the second stage, which in turn reduces the hydrogen required for hydroconversion. The NiMo and CoMo catalysts both catalyze the water-gas displacement reaction. The objective of this second stage of reaction is again to balance the deoxygenation reactions. This balance is made by using relatively low pressures from 6.89 barg to 55.2 barg (100-800 psig) along with the right choice of the catalyst. In conventional hydrodeoxygenation processes, pressures in the range of about 138 barg (2000 psig) to about 207 barg (3,000 psig) are commonly employed. This is because the processes are designed to convert the pyrolysis oils, which are extremely unstable and difficult to process at low H2 pressure.

After the hydroconversion step, the oil produced will be substantially deoxygenated such that it can be directly used as a carrier fuel after it is separated by means of high pressure separators 12, 13 and low pressure separator 14, by distillation in the form of petrol and diesel portions. In cases where large amounts of C4, C5, and C6 type hydrocarbons are produced, a refrigerated adsorber may be placed after the separator to recover the C4 and C5 hydrocarbons from the gas stream. A heavy portion of the liquid such as condensed in the separator 12 is cooled and used to adsorb the hydrocarbons C4 and C5 of the gas stream. A key aspect of this process is to adjust the temperature, pressure and spatial velocity to balance the decarboxylation, decarbonylation and hydrodeoxygenation level such that the entire H2 required for the process can be made by reforming the light gases which are produced within of the process. If excessive hydrodeoxygenation occurs, then too much H2 will be required for the process and the system will be conducted out of balance. Also, if excessive decarboxylation or de-carbonylation occurs, too much carbon will be lost to CO 2 and CO instead of being converted into liquid product form, as a result where the liquid productions will be reduced.

[029] After the hydroconversion step, the produced effluent is cooled substantially such that the gasoline and diesel boiling materials condense and only the light gases remain in the vapor phase. These gases (containing CO, CO2, CH4, ethane and propane) are sent to the steam reformer 15 along with the process water for conversion to H2 and CO2. A portion of these gases are burned in an oven or other burning material to heat the remaining portion of the gases to the steam reformer operating temperature of about 927øC (1700øF). Steam reformers require a 3/1 vapor-hydrocarbon ratio in their feed to push the equilibrium of the reaction, but this is much more than the amount required for the reaction. Steam is recovered and recycled internally in the steam reformer. CO2 is removed from the absorption process by pressure oscillation (PSA) absorption and the H2 is recirculated back to the first stage of reaction (hydrotropyysis) of the process. The liquid produced can be separated as diesel and gasoline fractions which are suitable for use as transport fuels.

[030] Furthermore, this process is also balanced with respect to water such that sufficient water is produced in the process to provide all the water required in the steam reforming step. According to one embodiment of this invention, the amount of water employed is such that the output of the process as a whole contains substantially only CO2 and liquid products, thereby avoiding an additional process step for the disposal of excess water. It will be appreciated by those of ordinary skill in the art that the use of steam reforming in combination with hydropyrrole and hydroconversion steps as presented herein makes sense only where the purpose is to provide a self-sustaining process wherein the ratio of O 2 to H 2 O relative to O 2 in the CO and CO 2 produced by the process is about 1.0. In the absence of such a goal, steam reforming is not necessary because the H2 required for the hydro-pyrolysis step can be further provided by external sources. If steam reforming were to be employed in the absence of the objectives set forth herein, the self-sustaining process of this invention could not be terminated in that the process output consists essentially of the liquid product and CO2.

According to one embodiment of this invention, the heat generated in the second reaction stage can be used to supply all or part of the heat required to conduct the hydro-pyrolysis step in the first reaction stage. According to one embodiment of this invention, the process also employs recirculation of the finished heavy products as a washing liquid in the second step as set forth hereinbefore to capture the process fines exiting the first stage pyrolysis reactor and controlling the heat of the first stage reaction. According to one embodiment of this invention, such liquid is also recirculated for hydroconversion and possibly for the first stage hydrotropyysis step to regulate the generation of heat at each step. The recirculation rate is preferably in the range of 3 to 5 times the feed rate of the biomass. This is necessary because hydrode-oxygenation is a strongly exothermic reaction.

According to one embodiment of this invention, the bio-mass feed is a high-lipid aquatic biomass such as algae or an aquatic plant, such as lemna, which allows the production of the same deoxygenated diesel oil as can be produced from the lipids extracted from algae or further lemma gasoline and diesel that can be produced from the rest of the aquatic biomass. This is particularly attractive because lipid extraction is expensive. On the other hand, conventional fast pyrolysis of algae and aquatic biomass would be very unattractive due to the characteristics of the uncontrolled thermal reactions of rapid pyrolysis that can degrade these lipids. Thus, the integrated process of this invention is ideal for the conversion of aquatic biomass as it can be carried out in aquatic biomass which is usually only partially dehydrated and still produce high quality diesel and gasoline.

The process of this invention provides several advantages over conventional processes based on rapid pyrolysis by the fact that it produces a stable, partially deoxygenated product with a negligible content under carbonized material from which the residual carbonized material can be easily separated by filtration in hot gas or by contact with a recirculated liquid; the hot vapors of the clean hot hydropyrolysis oil can be directly improved in grade to an end product in a second improved catalytically closed coupled process unit at about the same pressure as employed upstream; and the improvement of the degree of quality is performed quickly before degradation can occur in the vapor produced from the hydro-pyrolysis step.

[034] The liquid product produced by this process should contain less than 5% oxygen and preferably less than 2% oxygen with a low total acidity (TAN) content and should exhibit good chemical stability of polymerization or a reduced tendency to reactivity. In the preferred embodiment of this invention wherein the total oxygen content of the product is reduced to below 2%, the water and the hydrocarbon phases will be easier to separate into any normal separation vessel because the hydrocarbon phase becomes hydrophobic. This is a significant advantage when compared to conventional pyrolysis in which the water becomes miscible and mixed with the highly oxygenated pyrolysis oil. Table 1 shows an estimated material balance for a balanced hydrotropyysis + hydroconversion process according to this invention, using a mixed feed of wood. Because the fungible fuels produced in the disclosed process are low in oxygen, any excess water produced from this process is relatively free of dissolved hydrocarbons and will probably contain less than 2000 ppm of total dissolved organic carbon (TOC), making it suitable for irrigation in arid areas. In addition, the finished hydrocarbon product has now become easily transportable, has a low total acidity (TAN), and excellent chemical stability. In conventional fast pyrolysis, pyrolysis oils usually contain 50-60% oxygen in the form of oxygenated hydrocarbons and 25% dissolved water. Therefore, the final costs of transporting products for an integrated hydropyrrolysis + hydroconversion process of this invention are less than half of the costs of conventional rapid pyrolysis. In addition, the water produced in the proposed process becomes a valuable byproduct, especially for the arid regions.

Table 1. Estimated Material Balance for a Balanced Hydro-Hydrolysis Process + Hydroconversion Using Mixed Wood Feeding * * All H2 is produced by reforming light gases and no natural gas is needed One of the disadvantages of the process of this invention as described above is that it produces n-hexane (NCe) and n-pentane (NC5) in quantity, which is material in the gasoline boiling range but which is low in octane. Additionally, with a separately cellulosic, the process produces a material in the boiling range of very light gasoline and not much diesel fuel. One approach for processing the fuel assembly produced by this process may be to isomerize the product NC5 and NC6 in an isomerization unit in the petroleum refinery. However, NC5 and NC6 are very stable molecules, which conventionally require a very difficult multistage process for their transformation into higher boiling components. The required steps may involve dehydrogenation to produce olefins and then polymerization.

According to one embodiment of this invention, a hydrocracking catalyst is provided upstream or downstream of the hydroconversion step, thus isomerizing the normal pentane and normal hexane in the liquid products from the hydro-pyrolysis step and iso-xane , respectively, to increase the octane of the liquid products of the process. According to a particularly preferred embodiment as shown in Figures 3 and 4, the hydrocracking catalyst is provided between the hydro-pyrolysis step and the hydroconversion step of the process and receives the products emitted by the hydro-pyrolysis step. According to one embodiment as shown in Figure 4, the hydrocracking catalyst is disposed within a separate reactor 24 upstream of the reactor 11 of the hydroconversion step. According to another embodiment, as shown in Figure 3, the hydro conversion reactor comprises two compartments, one upstream compartment 22 and one downstream compartment 23, mutually communicated, and the hydrocracking catalyst is arranged in the upstream compartment in that the n-pentane and n-hexane of the hydro-pyrolysis step are converted into isopentane and iso-hexane, respectively, and the hydroconversion catalyst is disposed in the downstream compartment. According to another embodiment of this invention, as shown in Figures 2 and 5, the hydrocracking catalyst is provided downstream of the hydroconversion step. According to one embodiment as shown in Figure 2, the hydroconversion catalyst is provided in the upstream compartment 20 of the two compartment hydroconversion reactor in which the partially deoxygenated hydrotropyysis liquid from the hydropyolysis step of the integrated process is converted into a liquid substantially fully deoxygenated hydrocarbohydrate, a gaseous mixture comprising CO, CO 2 and light hydrocarbon (C 1 -C 3) gases, and the hydrocracking catalyst is provided in the downstream compartment 21. According to one embodiment, the hydrocracking catalyst is disposed in a separate vessel from the hydrocracking reactor 24 as shown in Figure 5.

According to one embodiment as shown in Figure 8, the hydrocracking catalyst is disposed within a hydrocracking reactor 27, substituting the hydroconversion reactor and completely eliminating the hydroconversion catalyst, in order to polymerize the oxygen containing molecules of the hydroconversion reactor. liquid product from the hydro-pyrolysis step while removing the oxygen from the structure. As a result, the product may be displaced towards products C12 and C18 and away from the molecules of the light gasoline boiling range, thereby producing materials in the diesel boiling range which are particularly suitable for use in truck engines and jet engines.

According to another embodiment of this invention, as shown in Figure 6, the hydrocracking catalyst may be arranged in a separate hydrocracking reactor 24 which operates in parallel with the hydroconversion reactor 11, thereby allowing the simultaneous and controlled polymerization and isomerization, which may allow a process configuration for the production of either gasoline or diesel fuel as desired.

[039] According to yet an additional embodiment of this invention as shown in Figure 7, the hydrocracking catalyst is provided in a hydrocracking reactor 26, replacing the hydro-pyrolysis reactor.

Suitable hydrocracking catalysts for use in the process of this invention are acid catalysts, catalysts containing metals which provide both a hydrogenation (from metal) function and an acid function. Representative of such catalysts are CoMo, NiMo or NiW catalysts, arranged on amorphous silica alumina, for example 75% SiO 2 and 25% Al 2 O 3. Any acidic, metal-containing, bi-functional catalysts which are capable of withstanding the operating conditions of the process of this invention may be employed.

While in the above-mentioned specification of this invention has been described in connection with some of its preferred embodiments, and many details have been presented for purposes of illustration, it will be apparent to those of ordinary skill in the art that the present invention is susceptible of additional embodiments and that some of the details described herein may be considerably varied without departing from the basic principles of the invention.

Claims (25)

A process for producing liquid products from biomass comprising the steps of: a) hydropyrolysis of the biomass in a fluidized hydrolyzolysis reactor containing molecular hydrogen and a fluidized bed of solid supported deoxygenation catalyst comprising Co and / or Ni, under hydropyrolysis conditions including a temperature of 260øC (500øF) at 1000øF (538øC), a pressure of from 6,89 barg (100 psig) to 55,2 barg (800 psig) and a time of residence of the gas in said hydro-pyrolysis reactor vessel less than one minute, producing a yield of the hydrotropyysis reactor comprising CO 2, CO and C 1 -C 3 gas, a partially deoxygenated hydrotropyysis product and carbonized material; b) removing said carbonized material from said partially deoxygenated hydro-pyrolysis product; c) hydroconversion under hydroconversion conditions including a temperature in the range of 260Â ° C (500Â ° F) to 454Â ° C (850Â ° F) and a pressure of 100 psig (6.89 barg) to 55.2 bar psig) of said partially deoxygenated hydrotropyysis product in a hydroconversion reactor using a hydroconversion catalyst in the presence of CO 2, CO and C 1 -C 3 gas generated in step a) to produce a substantially totally deoxygenated hydrocarbon liquid and a mixture gas comprising CO, CO2 and light hydrocarbon gases (C1-C3); d) steam reforming at least a portion of said mixture, producing reformed molecular hydrogen; and e) introducing said reformed molecular hydrogen into said reactor for the hydrotropyysis of said biomass, wherein the process is CHARACTERIZED in that the hydropyrolysis conditions of step a) also include an hourly space velocity of 0.2 to 10 g biomass / g catalyst / hr. A process as claimed in claim 1, wherein a portion of said substantially fully deoxygenated hydrocarbon liquid created in step c) is recycled to said hydrotropyysis reactor or to said hydroconversion reactor to control the temperature. A process according to claim 1, characterized in that at least one of said deoxygenation catalyst and said hydroconversion catalyst is a glass-ceramic material. A process as claimed in claim 1, characterized in that it further comprises a hydrocracking catalyst arranged upstream or downstream of said hydroconversion reactor, within said hydroconversion reactor or in a hydroconversion reactor upstream or downstream of said hydroconversion reactor. downstream reactor or wherein said hydrocracking catalyst is arranged in a separate hydrocracking reactor operating in parallel with said hydroconversion reactor. A process according to claim 4, characterized in that said hydrocracking catalyst is a metal-containing acid catalyst which provides both a hydrogenation function and an acid function. A process according to claim 4, CHARACTERIZED by the fact that said hydrocracking catalyst is disposed downstream of said hydroconversion catalyst. A process according to claim 1, CHARACTERIZED by the fact that said hydroconversion catalyst catalyses both a water-gas displacement reaction and hydroconversion reaction. A process according to claim 1, characterized in that said steps a) and c) are carried out at a substantially equal pressure. A process according to claim 1, characterized in that said hydroconversion is carried out at an hourly space velocity of 0.2 to 3 g of biomass / g of catalyst / hr. A process according to claim 1, characterized in that said substantially fully deoxygenated hydrocarbon liquid is separated into suitable diesel and gasoline fractions for use as carrier fuel. A process according to claim 1, CHARACTERIZED in that said carbonized material is removed from said fluidized bed reactor from only the top of said fluidized bed. A process according to claim 1, characterized in that step b) comprises bubbling gases out of said hydro-pyrolysis reactor through a recirculation liquid comprising a high-boiling portion of said substantially hydrocarbon liquid totally deoxygenated. A process according to claim 1, characterized in that the production of said process consists essentially of liquid product and CO2. A process according to claim 11, characterized in that said deoxygenation catalyst is granulated and sufficiently resistant to friction in such a way that it rubs against said carbonized material, thereby allowing removal of said carbonized material from said flow bed reactor only from the top of said fluidized bed. A process according to claim 1, characterized in that said carbonized material is removed from said fluidized bed reactor by the energy separation of the carbonized material employing at least one of an inertial, electrostatic, and magnetic process. A process according to claim 15, characterized in that said deoxygenation catalyst is a glass-ceramic material. A process according to claim 4, characterized in that said hydrocracking catalyst is arranged upstream of said hydroconversion catalyst. A process according to claim 1, characterized in that, in step d), reformed molecular hydrogen is produced in an amount sufficient for hydropyrolysis of said biomass. A process according to claim 1, characterized in that the steam reforming step (d) is carried out using water produced in step a) and in step c) to produce reformed molecular hydrogen. A process according to claim 1, characterized in that the hydroconversion pressure is in the range of from 6,89 barg (100 psig) to 34,5 barg (500 psig). A process according to claim 19, characterized in that the water produced in step a) and step c) is separated from the substantially totally deoxygenated liquid hydrocarbon. A process according to claim 1, characterized in that said deoxygenation catalyst and said hydroconverter catalysts have different catalytic activities. A process according to claim 22, CHARACTERIZED by the fact that the hydroconversion catalyst has a higher catalytic water vapor shift activity relative to the deoxygenation catalyst. A process according to claim 22, CHARACTERIZED by the fact that the hydroconversion catalyst has a higher acidity in relation to the deoxygenation catalyst. A process according to claim 22 characterized by the fact that the hydroconversion catalyst has catalytic polymerization activity to increase the yield of C12 and C18 product in the substantially fully dehydrogenated liquid hydrocarbon.